Safety system for hypodermic syringe and needle

ABSTRACT

A simple, economical, easy to manufacture and use system for protecting against unintended pricks from used hypodermic syringes and needles, and the leakage of fluid therefrom is disclosed. The system involves an adaptation to standard syringes comprised of a guide, and needle securing plunger which fits into the guide. Provision to prevent the needle securing plunger from falling out of the guide is included, as are needle securing plunger design considerations which serve to ensure the needle securing plunger will allow embedding a needle in a needle pocket at the end of the needle securing plunger, and which serve to provide natural spring from interaction of the guide and the needle securing plunger when the end of the needle securing plunger, (i.e., the needle pocket region), is in place over a needle tip. Additionally, a preferred packaging system to assure sterility and allow easy identification of needle or syringe length or gauge, etc. is disclosed. Also taught, is the method of use of the system to both protect and re-expose a hypodermic needle point.

The subject matter of this application was disclosed in DisclosureDocument No. 183,179.

TECHNICAL FIELD

The present invention pertains generally to hypodermic syringes andneedles and more particularly, the present invention focuses on a systemwith provision for protecting a needle attached to a syringe after thecombination has been used to prevent accidental "pricking" of unintendedpersons, and to prevent unintended fluid leakage from the syringe. Thepresent system is simple to use and easy to manufacture.

BACKGROUND

Hypodermic syringes and needles are used for injections and drawingblood in medical and veterinary settings throughout the world. In healthcare settings large numbers of patients require injections or bloodsampling services in short periods of time. The use of large numbers ofhypodermic syringes and needles under the constraints imposed by typicalhealth care environments, inevitably, leads to health care professionalsaccidentally pricking themselves. or others with a previously usedneedle, or alternatively, coming into contact with fluids which haveleaked from a syringe, the needle associated with which was not cappedafter use. The recent AIDS epidemic has heightened awareness of thepotentially devastating effect such accidents can have. Not only canpatients become mortally infected by a needle prick, or contact withfluid leaked from a syringe but health care professionals can as well. Aneedle prick can end the career of a health care professional, whichcareer took years to nurture, in but a second. The inevitable nature ofsuch occurrences has led creative people to design new systems andpropose methods of use of specialty hypodermic syringes and needles, oradaptations thereof, which have as their focus the minimization of therisk that unintended needle pricks and/or fluid spills from used systemswith uncapped needles will occur.

In recent years a number of patents have issued, the inventions in whichteach means by which the risk alluded to can be lessened. In evaluatingsaid inventions, a number of factors must be considered. The foremostfactor is, of course, the likelihood of success in achieving a lessenedrisk of unintended needle pricks and/or fluid spills from used systems.Generally, such likelihood is reduced in inverse proportion to the levelof difficulty involved in practicing the system or method of a giveninvention. The more difficult it is to use an invention, the less likelyit is to be successful or even used. Another consideration is thecomplexity of an invention per se. Accompanying complexity is theconsideration of the cost of manufacturing an invention.

An ideal system for lessening the risk of accidental needle pricks andfluid spills from used syringes would be very easy and economical tomanufacture and extremely simple to use.

A study of existing prior patents in relevant areas show that many priorinventions which provide means for securing a needle after use, arecomplex to manufacture (hence potentially expensive) and/or operate,(e.g. U.S. Pat. No. 4,631,057 to Mitchell; U.S. Pat. No. 4,425,120 toSampson; U.S. Pat. No. 4,666,435 to Braginetz; U.S. Pat. No. 4,664,654to Strauss; U.S. Pat. No. 4,693,708 to Wanderer; U.S. Pat. No. 2,674,246to Bower; U.S. Pat. No. 4,681,567 to Masters; U.S. Pat. No. 4,655,751 toHarbaugh; and U.S. Pat. No. 4,702,738 to Spencer).

A study of existing patents in the relevant area also shows that manyprior inventions which provide means of securing a needle after userequire two hands to use effectively, (e.g., U.S. Pat. No. 4,631,057 toMitchell; U.S. Pat. No. 4,573,976 to Sampson; U.S. Pat. No. 4,425,120 toSampson; U.S. Pat. No. 4,666,435 to Braginetz; U.S. Pat. No. 4,659,330to Nelson; U.S. Pat. No. 4,693,708 to Wanderer; U.S. Pat. No. 4,681,567to Masters; U.S. Pat. No. 4,655,751 to Harbaugh; U.S. Pat. No. 4,702,738to Spencer; and U.S. Pat. No. 2,571,653 to Bastien). The necessity ofusing two hands to operate a mechanism is a definite drawback. An idealmechanism should be easy to operate with one hand, perhaps by motionimparted by a user's thumb as a syringe rests on the surface formed bythe fingers of the same hand.

Some prior inventions involve a needle guard which must be rotated to beused, (e.g. U.S. Pat. No. 4,425,120 to Sampson; U.S. Pat. No. 4,666,435to Braginetz; U.S. Pat. No. 4,693,708 to Wanderer; U.S. Pat. No.2,674,246 to Bower; U.S. Pat. No. 4,702,738 to Spencer). In addition,some needle guards are free to rotate around a syringe even thoughrotary motion is not required for operation (e.g., U.S. Pat. No.4,631,057 to Mitchell; U.S. Pat. No. 4,573,976 to Sampson; U.S. Pat. No.4,655,751 to Harbaugh; U.S. Pat. No. 2,571,653 to Bastien). It is notnecessary to protect a needle point that a shield rotate, rather ashield must move longitudinally along a needle to accomplish the task.It is doubtful if any benefit provided by the rotational aspect of theshield justifies the added complexity in construction, and potential forblocking the ability to observe the contents of a syringe by therotational motion of the shield. Further examination of existing patentsshow that view of liquid in a syringe taught in said patents is by wayof two layers of plastic or glass, (e.g., U.S. Pat. No. 4,631,057 toMitchell; U.S. Pat. No. 4,573,976 to Sampson; U.S. Pat. No. 4,425,120 toSampson; U.S. Pat. No. 4,666,435 to Barginetz; U.S. Pat. No. 4,693,708to Wanderer; U.S. Pat. No. 2,674,246 to Bower; U.S. Pat. No. 4,681,567to Masters; U.S. Pat. No. 4,655,751 to Harbaugh; U.S. Pat. No. 4,702,738to Spencer; and U.S. Pat. No. 2,571,653 to Bastien). Any obstruction ofview in addition to a syringe wall, of the liquid in a syringe is anundesirable factor. Such obstruction simply serves no useful purpose.

Further study of existing patents show some inventions require springsin their construction (e.g., U.S. Pat. No. 4,664,654 to Strauss; andU.S. Pat. No. 2,674,246 to Bower). Springs are added complexity and itwould be preferable if any "spring" required could be a naturalconsequence of the design of an inventions parts so as to include suchnaturally, perhaps in the form of molded plastic parts with physical"memory".

Many existing inventions also provide needle shields which are open attheir end. That is the needle is inside a tubular structure orequivalent which is not closed at its end. Examples are the inventionsin U.S. Pat. No. 4,631,057 to Mitchell; U.S. Pat. No. 4,573,976 toSampson; U.S. Pat. No. 4,425,120 to Sampson; U.S. Pat. No. 4,666,435 toBraginetz; U.S. Pat. No. 4,664,654 to Strauss; U.S. Pat. No. 4,693,708to Wanderer; U.S. Pat. No. 4,681,567 to Masters; U.S. Pat. No. 4,655,751to Harbaugh; and U.S. Pat. No. 2,571,653 to Bastien). Two inventionsprovide caps to cover open ended needle shields, (e.g., U.S. Pat. No.2,674,246 to Bower and U.S. Pat. No. 4,702,738 to Spencer). Except forthese inventions, all those with open ended needle shields can allowfluid to leak out of a syringe. The obvious disadvantage of such is thatone could come into contact with fluid which has leaked from a syringeand be infected through a pre-existing wound. A safe needle guard shouldprovide for preventing leakage from a syringe without requiring adangerous recapping process in which two hands are required to perform.

It should also be noted that of the inventions alluded to, only that inU.S. Pat. No. 4,664,654 to Strauss does not require that a collar beplaced around the syringe itself to achieve its system, and only theinvention in U.S. Pat. No. 4,681,587 to Masters provides for a clearsyringe when the needle shield is mounted on a syringe. Both inventionsrequire two hands to operate as well.

A system which would provide for securing syringe needles to preventaccidental needle pricks and which would prevent fluid leakage fromsyringes when in place (i.e., closed end on needle when in place), andwhich would provide clear view of fluid in a syringe through one layer(i.e., no collar required on a syringe) of plastic or glass both priorto and after securing a needle; and which provides spring to ensureneedle securement by clever design of elements rather than by use ofsprings per se; and which does not require, or even allow, needle guardrotation; or require more than one hand to operate; and which is simpleand economical to manufacture would be of great utility. Such a systemis taught herein, directly.

DISCLOSURE OF THE INVENTION

The need for a noncomplex, economic and easy-to-use system which securesused syringe needles to prevent accidental pricking of unintendedpatients and medical professionals, etc. as well as prevent liquidleakage from a used syringe, while providing a clear view of liquid inthe syringe, is met by the present invention. The method of the presentinvention provides for one-handed operation and the system is designedso that spring action is accomplished without the use of springs per se.The spring action serves to ensure against a needle, once secured, frominadvertently becoming again free.

The system of the new invention comprises a syringe barrel to which islongitudinally attached a guide. The guide provides for a plunger, whichplunger fits into and slides within the guide. The plunger extendsbeyond the guide at both the needle and syringe end of the guide. At thesyringe end, the plunger is constructed to allow a user's thumb orfinger, etc. to press thereon and cause the plunger to move in theguide, thereby causing the end of the plunger at the needle end of theguide to extend further beyond the guide. The plunger is fabricated sothat it will bend toward the needle as it leaves the guide. This bendingaction causes the plunger to contact the needle and ride along it in av-shaped groove in the tip of the plunger until it reaches the end ofthe needle, at which time it bends over the tip of the needle.Simultaneously, at the opposite, syringe, side of the guide, the plungeris constructed so as to flare out. That is the plunger becomes slightlywider and, hence, more difficult to press into the guide. When a personremoves his or her thumb or finger from the syringe side of the plunger,the plunger has a natural "spring" or recoil tendency which causes theplunger to move slightly back toward the syring side of the guide.Because, however, the tip of the needle has already been covered by theopposite, needle, side of the plunger, the needle is caused to insertslightly into the plunger at the point of the needle-plunger contact.The plunger at that point contains a pocket to aid this action andenhance the effect. The result of the above described action is that aneedle is secured. The plunger then acts as a guard against accidentalpricking of patients, medical personnel, etc., and it also acts as aplug to prevent liquid from leaking from the syringe through the needle.

Provision is made, preferably by constructing the plunger and guide withteeth on the outside of the plunger and teeth on the inside of theguide, to prevent a plunger from falling back out of the guide prior touse. That is, once a plunger is inserted into a guide to its pre-useposition, it cannot be easily pulled back out. It can be easily pushedtoward the needle, however, when it is desired to secure the needle.

Should it be necessary to remove liquid from a syringe intentionally,the plunger can again be pushed forward so that the needle point is nolonger embedded in the pocket therein at the point where the needlecontacts the plunger. By then applying pressure on the plunger betweenthe point at which it leaves the guide and the location of the needlepoint (note this is safely away from the needle point itself) in thedirection of the needle, and perhaps slightly, back toward the syringebarrel, the plunger is caused to move away from the tip of the needle.The pressure applied to the plunger at the head syringe side thereof canthen be released and the needle tip thereby becomes re-exposed. Notethat simply releasing pressure at the syringe side of the plunger willcause it to naturally retract due to the flare out widening of theplunger at the entrance of the guide at the syringe side.

The present invention, in its preferred embodiment, requires thatsyringes have permanently attached needles and that specific plungers beused in conjunction with specific length needles and syringes, so thatproper coordination occurs during use. The syringes, the permanentlyattached needles and plunger-guide system are meant for one-time onlyuse.

The guide and plunger are of relatively small width compared to thecircumference of the syringe barrel, hence, do not significantly reduceor obstruct view of liquid inside the syringe.

SUMMARY OF THE INVENTION

Hypodermic syringes and needles are used for injections, and the drawingblood, in medical and veterinary settings throughout the world. Therecent AIDS epidemic has heightened awareness of the danger accidentalneedle pricks from used needles present to patients and medicalprofessionals, etc. Numerous patents have taught inventions which haveas their purpose the prevention of unintended needle pricks. A study ofrelevant prior patents, however, shows that no prior invention intendedto prevent accidental needle pricks and provides a simple economicalsystem for securing syringe needles which system comprises a guide andplunger mechanism with natural needle setting spring, which systemprevents leakage from a secured needle, but which system simultaneouslyallows unobstructed view of liquid inside an associated syringe andwhich system provides for a method of use which requires only one handto practice.

The present invention comprises a syringe with (in its preferredembodiment) a permanently attached needle, to the barrel of whichsyringe is attached a guide, into which guide a plunger is place. At theneedle end of the plunger, facing the needle, is located a pocketstructure, and at the syringe end of the plunger is located a structurevia which a person can place pressure with his or her thumb while thesyringe is held in the fingers of the same hand. The plunger, at theneedle end, is constructed with a tendency to bend toward the needle,and at the syringe end, a flare out increased width is present. Themethod of operation comprises applying pressure on the plunger at thesyringe end so that the plunger slides toward the needle and curves tocontact said needle until reaching and extending over the tip of theneedle. The pocket in the needle end of the plunger serves to encompassthe tip of the needle, and when pressure is released at the syringe endof the plunger, the plunger tends to naturally retract as a result ofthe flared out width of the plunger at the point it enters the guide. Itis important to note, in the present invention, that the plunger be of aproper length to accommodate the needle permanently attached to thesyringe, hence, different length plungers will be required for differentlength needles. The invention also provides means to prevent the plungerfrom sliding back out of the guide after it is placed in the guide inits pre-use position.

Finally, the entire syringe and needle will be packaged so that thesyringe, needle and needle guard apparatus can be kept sterile untilintentionally opened. The packaging will be designed with colors to codefor the length or gauge of the needle or syringe size, etc.

A purpose of the present invention is to provide a safe, easy tomanufacture and easy to use system for protecting against unintendedneedle pricks and/or spilled fluid by or from respectively a usedhypodermic syringe and needle combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a syringe with the present inventionincorporated herein.

FIG. 2 is a top view of the needle securing plunger.

FIG. 2a is a partial view of the bottom of the needle securing plunger.

FIG. 3 is a side elevational view of a syringe with the presentinvention incorporated therein, in a pre-use position.

FIG. 4 is a side elevational view of a syringe with the presentinvention incorporated therein, in a post-use (after drawing blood forinstance) position.

FIG. 5 is a side elevational view of a syringe with the presentinvention incorporated therein, in a post-use position, but manipulatedto re-expose a needle tip so fluid in the syringe can be intentionallyremoved.

FIG. 6 is a top planar view of a syringe with the present inventionincorporated therein, in a sterile container.

BEST MODES FOR CARRYING OUT THE INVENTION

Turning now to FIG. 1, there is shown a perspective view of a syringebarrel (1), a needle (3) and a syringe plunger (2), all said elementsbeing essentially identical to the elements in standard syringes whichare available off the shelf from medical and veterinary supply houses.Shown as well is a scale (1a) on the syringe barrel (1) which is easilyviewed by someone using the syringe.

Also shown in FIG. 1 or in FIGS. 2 and 3 is a guide (5) and needlesecuring plunger (4), (4a), (4b), (6) and (7) (herein after referred toas the NSP). The NSP slides into the guide (5) until the teeth (4b) onthe NSP, and teeth on the inner sides of the guide (5) identified as(5b) (in FIG. 3) mesh. This position is a "pre-use" position and theteeth (4b) and (5b) prevent the NSP from falling out of guide (5) oncethe NSP is in said "pre-use" position. The NSP has a head portion (4), ashank portion (4a), which shank portion can include ribbing identifiedas (4c), a needle pocket portion (6) and a needle guide structureportion (7), in addition to the teeth (4b). Note that the guide (5) canhave any inner lateral wall shape, and the NSP a complimentary shape,which causes the NSP to remain in the guide (5). Any complimentaryshapes for guide and plunger can be used.

FIG. 2 shows a top view of the NSP separate from the guide (5). Note theNSP narrows as one progresses from the head portion (4) toward the shankportion (4a). FIG. 2a shows the forward portion of the underside of NSP.In particular note the needle pocket (6).

FIG. 3 shows a side elevational view of the syringe barrel (1), needle(3), syringe plunger (2), guide (5), and NSP in a pre-use position.Pre-use as used here assumes the hypodermic will be used to draw blood.The hypodermic syringe plunger (2) would be extended as shown in FIGS. 4and 5 if the use is to be for an injection, and post-use would show thesyringe plunger (2) pushed into the syringe barrel (1). Note that theliquid measuring scale (1a) is unobstructed and liquid can be easilyviewed through the single wall of the syringe barrel (1).

FIG. 4 shows a syringe after it has been used to draw blood. Note theend of the syringe plunger (2a) is visible through scale (1a), whichscale is printed on the syringe barrel (1) directly. FIG. 4 also showsthe NSP has been pushed toward the needle (3) by a force "A" applied atthe NSP head (4). This has caused the needle guide structure (7) to makecontact with the needle and guide the needle pouch (6) over the needletip. The needle guide structure (7) curves to the needle as a result ofspring placed in the NSP material during manufacture. Any material whichtends to "remember" its shape can be used to fabricate the NSP andprovide this attribute.

When force "A" is released the NSP will have a tendency to pull-backand, hence, secure the needle tip in the needle pocket (6) againstaccidental leakage and unintended pricking of patients, medicalprofessionals, etc. The reason that the NSP will tend to pull back isthat the NSP is wider near the head (4) than it is at the shank (4a).The guide (5) will attempt to prevent the wider portion of the NSP fromremaining therein, as a result. This is another use of natural springresulting from clever design of a minimal number of invention elementalparts.

FIG. 5 demonstrates that should one wish to reopen the tip of theneedle, say to intentionally releast the fluid in the syringe, the actcan be accomplished safely. A force, indicated as "A" is applied to theNSP head (4) and a force shown as "B" is simultaneously applied to theNSP shank (4a) thereby causing the needle pocket (6) to move away fromthe tip of the needle. Ribs (4c) on the NSP can be included to aid withthis manuever, and can be helpful if the pressure applied, identified as"B" must be slightly back toward the syringe barrel to fully pull theneedle pocket (6) away from the needle tip. A reverse force at "A" willthen bring the NSP needle pocket back away from the needle tip. Theliquid in the syringe can then be removed in an intended fashion byapplying pressure to the syringe plunger head (2). One using the systemnever has his fingers near the needle tip.

FIG. 6 shows an overall container comprised of a cap (10) and acontainer barrel (10a). The entire system apparatus, including a pre-useneedle guard (9) will arrive at the location at which use will be madeof the system, in a totally sterile fashion. Present packaging exposesthe pre-use needle guard to the external environment. The needle is keptsterile, but the pre-use needle guard, which is often times removed froma needle and placed in a sterile setting, is contaminated on itsexterior.

Color coding of the container (10) and (10a) will be used to identifyneedle lengths and/or gauges and/or syringe volume capacity, etc.

It is to be noted that the present system requires that different lengthNSP's be used with different length needles. This is necessary socoordinated action can occur between the needle pocket (6) on the NSP,and the spring developed by the action of a widened NSP shank (4a) nearthe NSP head (4) attempting to enter the guide (5). For this reason, andfor the reason that the syringe and needles are intended for one timeuse only; the preferred embodiment utilizes a permanently attachedneedle and coordinated NSP. Users will not be able to change needles,and perhaps use one of a different length than was originally provided,and re-use the system, in the preferred construction. The guide (5) canbe specially fabricated into a syringe barrel, or manufacturedseparately and attached thereto.

It should be obvious from the foregoing that the present inventionprovides a combination of features not available in any other knownprior invention.

Having hereby disclosed the subject matter of this invention, it shouldbe obvious that many modifications, substitutions and variations of thepresent invention are possible in light of the teachings. It is,therefore, to be understood that the invention may be practiced otherthan as specifically described and should be limited in breadth andscope only by the claims.

I claim:
 1. A retrofit system for securing a hypodermic syringe and needle after use, to prevent accidental pricking of patients or medical professionals, etc., and to prevent unintended leakage of fluid from the syringe portion of the hypodermic through the attached needle comprising a guide, which attaches longitudinally to the barrel of the syringe; which guide provides an internal space into which a needle securing plunger can slide; which needle securing plunger, at the syringe end, thereof, has a head portion suitable for application of pressure by a user's thumb or finger, etc., followed by, as the length of the needle securing plunger is transversed, a tapering width dimension, which width dimension, becomes a smaller constant width as one follows the needle securing plunger toward the distal needle end thereof, which constant width is slightly smaller than the width of the space in the guide so that the needle securing plunger can slide into said guide; which guide and needle securing plunger further comprise teeth on the outer side of the needle securing plunger and on the inner side of the guide so that when the needle securing plunger is slid into the guide the teeth thereon move past the teeth in the guide, so that the needle securing plunger will not thereafter easily slide back out of the guide; which needle securing plunger further comprises, at the distal end thereof, a needle pocket on the bottom side thereof and a "v" shaped needle guide structure as viewed from the top or bottom of the needle guide structure; and which needle securing plunger is constructed so as to have a natural spring or tendency to curve toward the needle as the needle securing plunger is caused to move through the guide when pressure is applied to the head of the needle securing plunger, so that the needle pocket will naturally move to encompass the needle point as the needle securing plunger is caused to move as just described.
 2. A retrofit system for securing a hypodermic syringe and needle after use as in claim 1 in which the point at which the needle securing plunger begins to taper into a greater width as the needle securing plunger is transversed from the distal end toward the head of the needle securing plunger, enters the guide as the needle securing plunger is caused to move by the application of pressure on the head of the needle securing plunger by a user's thumb or finger, etc., at the same time the needle pocket encompasses the needle point, so that the needle securing plunger will have a natural tendency to retract from the guide and thereby firmly secure the needle point in the needle pocket, when said applied pressure is released.
 3. A hypodermic syringe and needle which provides means for securing the needle thereof after use, to prevent accidental pricking of patients or medical professionals, etc. and the unintended leakage of fluid from the syringe portion of the hypodermic through the attached needle comprising, a syringe barrel which is similar to conventional syringe barrels but which further comprises a guide attached longitudinally to the syringe barrel, which guide provides an internal space into which a needle securing plunger can slide; which needle securing plunger, at the syringe end thereof, has a head portion suitable for application of pressure by a user's thumb of finger, etc., followed by, as the length of the needle securing plunger is transversed, a tapering width dimension which width dimension becomes a smaller constant width as one follows the needle securing plunger toward the distal needle end thereof, which constant width is slightly smaller than the width of the space in the guide so that the needle securing plunger can slide into said guide; which guide and needle securing plunger further comprise teeth on the outer side of the needle securing plunger and on the inner side of the guide so that when the needle securing plunger is slid into the guide so that the teeth thereon move past the teeth in the guide, the needle securing plunger will not thereafter easily slide back out of the guide; which needle securing plunger further comprises, at the distal end thereof, a needle pocket on the bottom side thereof and a "v" shaped needle guide structure as viewed from the top or bottom of the needle guide structure; and which needle securing plunger is constructed so as to have a natural spring or tendency to curve toward the needle as the needle securing plunger is caused to move through the guide when pressure is applied to the head of the needle securing plunger, so that the needle pocket will naturally move to encompass the needle point as the needle securing plunger is caused to move as just described.
 4. A hypodermic syringe and needle which provides means for securing the needle thereof after use as in claim 3 in which the point at which the needle securing plunger begins to taper into a greater width as the needle securing plunger is transversed from the distal needle end toward the head of the needle securing plunger, enters the guide as the needle securing plunger is caused to move by the application of pressure on the head of the needle securing plunger by a user's thumb or finger, etc., at the same time the needle pocket encompasses the needle point, so that the needle securing plunger will have a natural tendency to retract from the guide and thereby firmly secure the needle point in the needle pocket, when said applied pressure is released. 